Rensselaer researchers have developed a new set of modeling tools that could enable safer, more accurate, and more effective radiation therapy and nuclear medicine imaging procedures for pregnant women.

Radiation is a doubled-edged sword: It holds the power to cure cancer, but if used improperly it can also cause serious damage to the human body. The situation is even more critical with pregnant females, as any errant radiation could severely harm and impede the growth of the fetus.

“The human body is a particular challenge to model because of its wide variety of organs, each with a complex and unique shape,” says X. George Xu, professor of nuclear and biomedical engineering at Rensselaer, who is leading the project. “Pregnant females are even more difficult to model using current methods, so we took an entirely new approach.”

Physicians use advanced computer simulations to determine the correct dose of radiation to administer to patients. These computer simulations are based on sophisticated virtual models of the human body. About 30 of these models, sometimes called “phantoms,” have been developed worldwide.

The data needed to build such models, however, requires extensive X-rays and computed tomography scans. Since pregnant patients are prohibited from undergoing X-rays or other imaging procedures, there has never been enough data to create an accurate phantom of a pregnant woman.

Conventional methods of phantom creation simply cannot account for the rapid changes of a pregnant woman’s internal physiology as her organs shift to accommodate the growing fetus. So Xu and his team turned to boundary representations (BREP) tools, which are more flexible and feature a more robust toolbox for manipulating the surface of model components. They created 3-D models of pregnant females at various gestational stages: three months, six months, and nine months.

“These new models should be extremely useful for understanding the risks of radiation, and for better planning radiation imaging and treatment for pregnant women,” Xu says. “The tools we have developed for this research should also open up several new avenues for improving the field of radiation dosimetry.”